Our new interactive graphic compares the generations today and in the years that each generation was young (ages 21 to 36) to demonstrate the sea change in young adults’ activities and experiences that has occurred over the past 50 years.

Almighty God, you alone can bring into order the unruly wills and affections of sinners: Grant your people grace to love what you command and desire what you promise; that, among the swift and varied changes of the world, our hearts may surely there be fixed where true joys are to be found; through Jesus Christ our Lord, who lives and reigns with you and the Holy Spirit, one God, now and for ever.Amen.

Reich: I think so. I know there are extremists who are interested in genealogy and genetics. But I think those are very marginal people, and there’s, of course, a concern they may impinge on the mainstream.

But if you actually take any serious look at this data, it just confounds every stereotype. It’s revealing that the differences among populations we see today are actually only a few thousand years old at most and that everybody is mixed. I think that if you pay any attention to this world, and have any degree of seriousness, then you can’t come out feeling affirmed in the racist view of the world. You have to be more open to immigration. You have to be more open to the mixing of different peoples. That’s your own history.

Newer findings complicate the story, however. In a study published last June in the Journal of Human Genetics, researchers sequenced the mitochondrial DNA of 12 Yamnaya individuals, along with their immediate predecessors and descendants. The remains were found in burial mounds, or kurgans (from which the theory takes its name), in modern-day Ukraine. They had been buried in layers atop one another from the end of the Stone Age through the Bronze Age, between about 4500 and 1500 B.C.—the same time as the genetic replacement event in Europe. The earliest and midrange specimens’ mitochondrial DNA (which is inherited from the mother) was almost entirely local. But the mitochondrial DNA of the most recent specimens included DNA from central Europe, including present-day Poland, Germany and Sweden. This discovery indicates that “there were pendulum migrations back and forth,” says lead author Alexey Nikitin

This survey is just the latest exhibit in a mounting case that suggests students have been presented with a warped view of the tradeoffs associated with unfettered free expression. Inclusivity is not in conflict with free speech. Whoever taught these students that these two phenomena were contradictory did them and the nation a terrible disservice.